Area sources and their importance for population exposure (Dispersion modelling in Taiyuan, China) Liu, Li (Norwegian Institution for Air Research/UIO) Larssen, Steinar (Norwegian Institution for Air Research) Cao, Jie (Shanxi Environmental Information Center) Zhang, Daisheng (Shanxi Environmental Information Center) Oct.2004 Oslo, Norway

Master Plan Against Air Pollution in Shanxi Province Data collection (Emission etc.) A dispersion model system (AIRQUIS) has been used for cities to study surface concentraions and exposures for basecase (2000) and different control options and scenarios By using model results and cost-benefit analysis in order to have action plan for air pollutions reduction

Master Plan Against Air Pollution in Shanxi Province Datong Taiyuan Yangquan Model studies in 3 cities 11 cities analysis on province level Will use Taiyuan as an example to show the importance of contributions by point sources and area souces (house holds etc.)

Pollution situation in Taiyuan Days above upper limits (2000) 75% days SO 2 above limits 68% days TSP above upper limits 8% days NOx above upper limits

Taiyuan Emission Database SO 2 Point sources : - 56 industries stacks Area sources : - Households third industry companies small industries TSP Point sources : - 85 industries stacks Area sources : - Households third industry companies small industries

Emission Inventory SO 2 Point sources : - Emission: 130,477 ton/year Area sources : - Emission: ton/year 47.9% Households 34.0% Third industry companies 18.1% small industries TSP Point sources : - Emission: ton/year Area sources : - Emission: ton/year 31.0% Households 35.2% Third industry companies 33.8% Small industries

Taiyuan administrative area /The AirQUIS model grid, Point source locations/ Total area source emissions in each of the districts. Point sources: SO2: 247 stacks TSP: 221 stacks

Seasonal variation factor Heating season SO2: 1.6 TSP: 1.2

Contribution to concentration and exposure (SO 2 ) (Simulation experiments) Basecase: Emission in year 2000 point sources/households Scenario 1: Emission control to households Emission reduction: ton/year Scenario 2: Emission control to power plants Emission reduction: ton/year

Surface concentration (All point sources) Surface concentration (Households)

Exposure Number of persons exposed to SO 2 concentration above 60ug/m 3 in each grid (1km × 1km)

Exposure to SO 2 pollution (All point sources) Exposure to SO 2 pollution (Households)

Improvement of surface concentration (Control options applied to Power Plants) Improvements of exposure to SO2 pollution ( after Control options applied to Power Plants)

Improvement of surface concentration (Control options applied to households) Improvements of exposure to SO 2 pollution ( after Control options applied to households)

Summary: 1.SO2 emission from point sources is smaller than area sources in Taiyuan. Emission from house holds sector is about 2/3 of total point sorces emssions. 2.The TSP emission from area sources is about 3 times of emission from point sources. Emission from house holds sector is about the same compared with total point sources. 3.The emissions both for SO2 and TSP from ´The third industrial companies´ are important as well. Maybe less import for indoor air quality, but it has strong impact on surface concentrations. 4.Area sources have much higher risk for increasing the surface concentration and population exposure to air pollution 5.The control options applied to area sources are much more efficient to improve the air quality and health damage